The present invention relates to an electronic component mounting apparatus and an electronic component mounting method for mounting an electronic component on a circuit board.
An electronic component supplied in a state of a semiconductor wafer of a semiconductor chip or the like is mounted on a circuit board of a lead frame or the like by an electronic component mounting apparatus having a supply apparatus exclusive for taking out a semiconductor chip in a state of being adhered on a sheet. According to the supply apparatus, in order to pick up the electronic component adhered on the sheet without a positional shift, an image of the electronic component constituting an object of pick up by a component recognizing camera to recognize a position thereof (refer to, for example, Japanese Patent 3511841).
According to the Japanese Patent, there is constructed a constitution in which the camera is fixedly arranged on an upper side of a moving table holding the semiconductor wafer and moving in a horizontal face, and in pick up operation of taking out the electronic component, the moving table is driven based on a result of recognizing the position by the component recognizing camera and the electronic component constituting the object of pick up is positioned to a pick up position set at a fixed position.
In recent years, with an object of promoting productivity of an electronic component mounting apparatus, in place of the above-described constitution of the prior art example, there is adopted an electronic component mounting apparatus having a constitution of taking out an electronic component from a component supply portion an XY position of which is fixed. According to such a constitution, a position of picking up the electronic component is not fixed and the electronic component is picked up from an arbitrary position on a sheet. Therefore, according to the above-described constitution, there is adopted a constitution having a camera moving mechanism which moves the camera for recognizing the position of the electronic component at the component supply portion to an arbitrary position.
However, according to the above-described constitution of moving the camera, a variation in position recognizing accuracy is brought about in recognizing the electronic component by the camera by being caused by a variation in a relative relationship between a camera coordinates system and a machine coordinates system of the mounting apparatus by a mechanism error of aging thermal elongation or contraction of a mechanism element of a ball screw or the like constituting the camera moving mechanism. Further, when the electronic component is picked up based on the unstable result of detecting the position, there is a problem that a failure in pick up is liable to be brought about by a positional shift. Further, the problem becomes particularly significant with an increase in a distance of moving the camera by large-sized of the semiconductor wafer.